Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 17991

GRB 150702A: Swift-XRT observations
2015-07-05T11:52:48Z (9 years ago)
Phil Evans at U of Leicester <>
P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'ai (INAF-IASFPA), T.G.R.
Roegiers (PSU), L.M. McCauley (PSU), J.A. Kennea (PSU), J.P. Osborne
(U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester) and
P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 150702A (Vianello et al. GCN Circ. 17989),
collecting 4.5 ks of Photon Counting (PC) mode data between T0+167.6 ks
and T0+180.0 ks. 

Two uncatalogued X-ray sources have been detected, however none of them
is above the RASS limit or shows definitive signs of fading. Therefore,
at the present time we cannot identify which, if any, is the afterglow.
Details of these sources are given below:

Source 1:
  RA (J2000.0):  53.1085  =  03:32:26.05
  Dec (J2000.0): -57.0628  =  -57:03:46.1
  Error: 9.8 arcsec (radius, 90% conf.)
  Count-rate: (3.6 +/- 1.7)e-3 ct s^-1
  Flux: (1.42 +/- 0.67)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 2:
  RA (J2000.0):  52.7486  =  03:30:59.65
  Dec (J2000.0): -56.9320  =  -56:55:55.1
  Error: 7.7 arcsec (radius, 90% conf.)
  Count-rate: (1.57 [+0.85, -0.66])e-3 ct s^-1
  Flux: (6.3 [+3.4, -2.6])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at

This circular is an official product of the Swift-XRT team.
Looking for U.S. government information and services? Visit